The present invention relates to a stripper for an organic polymer type radiosensitive resist used in the production of IC, LSI, or the like and more particularly to a stripper for fluoroalkyl .alpha.-haloacrylate polymers used as a deep ultraviolet and electron beam resist.
Heretofore, as the process for stripping from a substrate polymers used as radiosensitive resists such as poly(methyl methacrylate) and poly(methyl isopropenyl ketone), there have been known a wet process which employs concentrated sulfuric acid, concentrated sulfuric acid-hydrogen peroxide, or organic solvent, and a dry process which employs oxygen plasma. However, according to the process which employs a stripper consisting mainly of concentrated sulfuric acid, poly(fluoroalkyl .alpha.-haloacrylate) and copolymers thereof are poor in solubility and not stripped to a satisfactory extent. And according to the process which employs an organic solvent, the polymers may remain on the substrate in small amounts and it is difficult to obtain a mask or chip in high yield. In both processes, moreover, a resist which has been treated with plasma is more difficult to be stripped.
The process using oxygen plasma is an effective process, but is unsuitable for stripping a resist portion remaining thick on the edges and the back of the substrate.